I know that these areas will not stain as dark as hands/feet but I've never been happy with the results. I have a nice dark mix but in a festival setting I find myself trying to discourage people from getting henna in those places because I know it won't be as dark and I want them to be happy with the results. I clean the area well with alcohol and also seal with lemon juice and sugar but just can't seem to get the dark stains that I see in some of the pics people post. What tips would you recommend for a festival setting?

The only things I know to do that you didn't mention are using terps, leaving the paste on up to 8 hours, and working to keep the body warm while the paste is on. Oh! And make sure to avoid water as much as possilbe the first day after removing paste. It sound like you know what you're doing and have already thought of those things.

The fact is you're right, it will never get as dark on the torso as other places. I do what you do and try to be honest with your clients about what they can expect. What else can you do!?

I would echo what Jen says, one of the best things that you can do is to try to encourage your clients to leave the paste on, sealed with lemon sugar for at least 8 hours. I have done some tests on myself and and I got significantly better longer lasting colour on the parts that I left on for 8 hours and 12 hours.

It can be tough to get someone who walks into a festival booth to keep the henna on for an extended period of time. When people ask for something on the chest/shoulder/back. I usually try to steer them towards a thicker design - something with bold lines, e.g. tribal-ish. The thick layer of paste will take a little longer to dry, but it will thoroughly saturate the skin underneath and will usually result in a nice stain. I would also recommend terping the paste - it just works so much better on these tough-to-stain areas.